This application pertains to the art of grinding mills and, more particularly, to liner plates for grinding mills. The invention is particularly applicable to liner plates for the end walls of grinding mills and will be described with reference thereto. However, it will be appreciated that features of the invention can be used for liner plates located in other areas of a grinding mill.
Grinding mills include a shell having a generally cylindrical central wall and opposite end walls through which central inlet and discharge openings are provided for material processed in the mill. The inside of the shell is lined with replaceable liner plates which line the cylindrical wall and the inlet end walls have raised ribs commonly known as lifter bars for lifting material during rotation of the mill shell for achieving optimum grinding action. The lifter bars wear away as the material being ground slides therealong.
When the lifter bars are cast integral with the liner plates, the entire liner plate must be replaced in order to replace worn lifter bars. Therefore, several different arrangements have been used for providing lifter bars which are separate from the liner plates and can be replaced without replacing the liner plates. However, in known arrangements of this type, common bolts are used for securing the replaceable lifter bars and liner plates to one another and to the mill shell. Removal of the bolts for replacing a separate lifter bar often causes the liner plate to fall away from the shell. For this reason, liner plates of this type have been made relatively small so they can be handled more easily during installation and during replacement of the lifter bars.
It would be desirable to have an arrangement wherein lifter bars could be replaced while leaving the associated liner plate securely fastened to the mill shell.